Techniques are described for reusing downstream-assigned labels when establishing a new instance of a label switched path (LSP) prior to tearing down an existing instance of the LSP using make-before-break (MBB) procedures for RSVP. The techniques enable a routing engine of any non-ingress router along a path of the new LSP instance to reuse a previously allocated label for the existing LSP instance as the downstream assigned label for the new LSP instance when the paths of the existing LSP instance and the new LSP instance overlap. In this way, the non-ingress router does not need to update a label route in its forwarding plane for the reused label. When the new LSP instance completely overlaps the existing LSP instance, an ingress router of the LSP may avoid updating an ingress route in its forwarding plane for applications that use the LSP.

In one embodiment, a method comprises creating, in a computing network, a loop-free routing topology comprising a plurality of routing arcs for reaching a destination network node, each routing arc comprising a first network node as a first end of the routing arc, a second network node as a second end of the routing arc, and at least a third network node configured for routing any network traffic along the routing arc toward the destination node via any one of the first or second ends of the routing arc, the loop-free routing topology providing first and second non-congruent paths; and forwarding bicasting data, comprising a data packet in a first direction from a network node and a bicasted copy of the data packet in a second direction from the network node, concurrently to the destination node respectively via the first and second non-congruent paths.

A path discovery process is provided for discovering a lowest cost combination of a plurality of paths from the source node to the destination node via links between pairs of nodes along the paths. A path discovery messages from a source node is forwarded through the network. Prior to forwarding the path discovery message a node tests one or more conditions for disabling the forwarding. Upon receiving an instance of the path discovery message, this may include testing whether no other instance of the path discovery message has both smaller cost and a previous path that contains only nodes that occur also in the path of the received instance. Furthermore, this may include testing whether a destination of the path discovery message was also a node to which a preceding node along the path has a further link, and a cost of the path from the preceding node to the next node via said further link is not larger than the cost of the path from the preceding node to the next node. Furthermore, this may include testing whether the node has a further link to the destination node and the cost associated with the link to the next node is not less than the cost associated with the further link to the destination node.

A tunnel management device includes: a central processing unit configured to manage a tunnel that establishes a virtual network to be overlaid on a IP network; and a memory coupled to the central processing unit, wherein the central processing unit: extracts a second tunnel in the virtual network that uses a second route in the IP network where a number of times a portion of a first route in the IP network is used by a first tunnel in the virtual network is used is minimized.

There is provided mechanisms for routing packets between a terminal device and a control system node via intermediate nodes on wireless paths in a wireless network. A method includes obtaining information on disturbances of wireless paths used for communicating packets of a traffic flow between the intermediate nodes in the wireless network. The method includes determining, based on the information on disturbances, mutual correlation between the disturbances of the wireless paths. The method includes routing the packets of the traffic flow between the terminal device and the control system node via some of the intermediate nodes and along disjoint wireless paths, whereby the packets are transmitted in parallel on the disjoint wireless paths, and wherein the disjoint wireless paths have mutual correlation not higher than a threshold correlation value.

A relay node within a network, the network further comprising at least one donor node coupled to the relay node, and a mobile termination coupled to the relay node and at least one donor node, the relay node comprising means for: receiving a configuration message; configuring the relay node, based on the configuration message, to perform at least one of: receiving packets from the mobile termination and originating from one of the donor nodes; and sending packets to one of the donor nodes by transmitting them to the mobile termination.

A data link error feedback signaling system includes a transmitting network device and a receiving network device. The receiving network device may be operable to receive a network data unit from the transmitting network device over a data link, detect an error in the network data unit, and provide data link integrity information based on the error to the transmitting network device. The receiving network device may provide the data link integrity information by marking the data link flawed in a routing protocol, transmitting the data link integrity information via an informational protocol, and so on. The transmitting network device may respond to the data link integrity information, such as by marking the data link less preferred, marking the data link down, transmitting an alarm regarding the data link to a network operator, omitting taking an action upon determining that errors are below an error threshold, and so on.

Networks comprising multiple non-overlapping communication topologies are presented. The networks can include a fabric of interconnected network nodes capable of providing multiple communication paths among edge devices. A topology manager constructs communication topologies according to restriction criteria based on required security levels (e.g., top secret, secret, unclassified, etc.). Established topologies do not have overlapping networking infrastructure to within the bounds of the restriction criteria as allowed by the security levels.

A system, and corresponding method, is described for finding the optimal or the best set of routes from a master to each of its connected slaves, for all the masters and slaves using a Network-on-Chip (NoC). More precisely, some embodiments of the invention apply to a class of NoCs that utilize a two-dimensional mesh topology, wherein a set of switches are arranged on a two-dimensional grid. Masters (initiators or sources) inject data packets or traffic into the NoC. Slaves (targets or destinations) service the data packets or traffic traveling through the NoC. The NoC includes switches and links. Additionally, the optimal routes defined by the system includes moving the traffic in a way that avoids deadlock scenarios.

A method and apparatus for path computation includes generating a path computation element communication protocol (PCEP) message, whereby the PCEP message comprises a characteristic associated with a level of protection of a Protection Label Switch path (LSP) with a Working LSP; and transmitting the PCEP message for path computation.